hello around what percentage of windows games not dos, from 1995 to 2001 will play as good or better on a xp build

What good would a percentage do for you?
What games are you going to play?
It sounds like you are asking if a seperate XP computer would be "better" than a seperate 98 computer? Yes and no.

and would the age of hardware matter?

Why wouldn't it?

like if i used an i5 3570 and gtx 750 ti, would that cause any problems with compatibility or speed,than if i used an pentium 4 and a gpu from that time?

It can and it can not.

lastly what about using a 98 vm on windows 10

What about it?
What virtual machine software are you talking about?
What games?

what percentage of games from 1995 to 2001 will play as good or better compared to a high end 98 build?

See above.

If you want to know if XP can run more Windows games than Windows 98 then obviously it is a yes. For games with issues they can be patched or tweaked, for the few remaining that do not work or do not work well then run them on 9x.

If I were to hazard a guess I'd say 80-95% of games that'll run on Win9x will also run on WinXP one way or another. I don't think anyone can give a conclusive answer because there are litterally thousands of games made in that time frame and some are very obscure or mostly forgotten.
Apart from CPU speed sensitivity graphics card generation and driver will be the biggest issue but if I'm not mistaken you can use a GeForce FX series card with PCIe interface alongside a newer card and switch primary adaptors for better compatibility.
Last but not least there's Glide emulation which will also help.
For most games there are ways (patches, re-releases, compatibility mode, VMs etc.) to run them on more modern OS (Win10 i.e.) and in fact this is the declared purpose of this whole forum. 😉
But as long as you're not coming up with a list of games you want to play I don't think anyone will be able to tell you wether your gaming experience will profit from using an old computer to play them.

i dont have any specific game list right now,im about to make on but it will be hundreds of games from that time period, the reason i would like an percentage estimate, is so i can find out if its worth to buy a 98 pc.

matthi321 wrote on 2020-10-01, 17:47:

is so i can find out if its worth to buy a 98 pc.

Are there any games you want to play right now that you cannot adequately run on your current PC for some reason? Because otherwise the answer is probably "no" – you will spend a lot of time and probably a lot of money trying to configure this thing, and then it will sit in a corner and collect dust.

It really just depends on the specific games you want to play. I haven't met anyone who realistically wants to play through thousands of Windows-only 1995-2002 games. Most folks seem to end up having a collection of nostalgia or games that they'd always wanted to try but couldn't get back in the day for whatever reason - somewhere in the double-digits neighborhood.

As far as running late 90's games on Xp instead of Windows 98, as others have said - most either work fine or can be made to work more or less fine though I would imagine you may run into some issues since Windows 9x runs on top of DOS and there may be some games you want to play which need that underlying DOS stuff present even if they are technically Windows binaries.

right now i have 7th Legion which i cant install, i have war wind that works but is kinda laggy when moving units thougt that might be just how the game play. and midtown madness which is very laggy even tho i did the instruction for it on pcgamingwiki. but i have had many more old games dowloaded over the years on windows 10 which didnt work, and so i just deleted them.

matthi321 wrote on 2020-10-01, 19:00:

right now i have 7th Legion which i cant install

It seems to be available on GOG and Steam, so there's got to be some workaround. You'll just have to decide for yourself: is researching the workaround (or just buying the game again) for things like this worth more time and money to you than it would be to set up a complete Windows 98 PC? No one can make that decision for you.

but i have had many more old games dowloaded over the years on windows 10 which didnt work, and so i just deleted them.

When you download old games, you run the risk of getting an incomplete or badly-cracked package that won't work correctly even if you have a proper "period-correct" Windows 98 PC.